A new designing concept to realize multifunctional structural material systems is proposed and demonstrated in this paper. The concept can be explained as follow: There exist a couple of competitive structural materials which normally compete with each other because of their similar and high mechanical properties, and they tend to have secondary properties which are different from each other or opposite among them. So if they are combined together to make a composite, the similar properties, normally high mechanical property, can be maintained, and the other dissimilar properties conflict with each other, which will generate functional properties. According to the proposed concept, a CFRP (carbon fiber reinforced plastics)/aluminum laminate was fabricated and its actuation capabilities and multifunctionality were successfully demonstrated. A titanium fiber/aluminum matrix composite was also fabricated, where the fiber was oxidized for electrical insulation and strengthening. This material system is very simple, but it can generate many useful functions such as heating, actuation, temperature sensing, deformation sensing and healing.